What is the variance for the critical path?

$\backslash$table$[[$Activity$,\backslash$table$[[$Optimistic$],[$Time$],[($Weeks$)]],\backslash$table$[[$Most$],[$Likely$],[$Time $(],[$weeks$)]],\backslash$table$[[$Pessimistic$],[$Time$],[($weeks$)]]],[$A$,8,10,12],[$B$,4,10,16],[$C$,4,5,6],[$D$,6,8,10],[$E$,4,7,12],[$F$,6,7,9],[$G$,4,8,12],[$H$,3,3,3]]$

$9\mathrm{.}91$

$6\mathrm{.}66$

$5\mathrm{.}13$

$5\mathrm{.}6$